The degree of laser power dangerous classifications are CI:<0.4mw, CII:0.4-1.0mW, CIIIA:1-5mW,  CIIIB:5-500mW, CIV:>500mW
    Manufacturer must put on warning labels on CII , CIIIA, CIIIB, CIV. 

1. CI:<0.4mW ( Not dangerous laser )

    This grade's laser has no any creature damage when being pointed , this level should be extreme safe for human because if point to skin , do not have any feeling , even use eye to see too . So it is absolutely safe . They might use on CD player or other small equipments .

2. CII:0.4-1.0mW ( Low power laser )

    This grade of laser won't injure skin , would not cause fire , and because of low power , when it point to human eyes ,  eye has enough time to blink , or turn head away to avoid these strong light . These are called "within reaction time " , the laser seems would not hurt people eyes too , but human eye can not see it for a long time , or it might cause hurt on Retina . 

3. CIIIA:1-5mW  ( Medium power laser )

     This grade laser still won't injure skin but in some situation , it might hurt eyes or even cause a blind . For example if laser beam pass lens , the laser beam might concentrate , then it become dangerous . This grade's laser should be signal light to show it is working or not . Better to have  a key switch too .

4. CIIIB:5-500mW  ( High power laser )

     This grade laser can hurt human eyes in whatever situation , as it is power higher enough , eyes has not enough time to blink , and people's skin can be injured , even it can cause a fire . Moreover , if point the laser to wall , the reflective light is still strong , it hurt eyes without sense . 

     This kind of laser should have Key switch , safety appliance , signal light , cut-off switch to stop laser at any time , warning label . It is better to wear laser protector for eyes before turn it on . 

5. More than 500mW ( Extreme Industry laser )

     This grade laser should mainly use on industry field or military field . For example laser cutting machine , imagine that the 1000mW CO2 laser can drill holes on steel plate ! Only typical man can touch the button switch . 

     However , according my practice :

     10-30MW has no feeling when use finger to touch laser beam , 30-50MW has little feeling of heat , 100-200MW feels quite hot , 200-600mW i dare not touch already , 1000mW i dare not go to see the beam . 

     Thanks your reading and sorry for my poor English . 

Good quality one always start strong and all along strong laser beam , it won't goes weak unless the battery is out .

Poor quality maybe start strong but soon the laser beam goes weak , it can not recoverable by changing new battery . 

Thanks for reading . 

When got idea , i have to use different software to assemble it . It cost lots of time .

But we think that is worth . because those are very interesting advertisement . 

In order to save it and let us track what we did , i save it here for people review . 

For this 1st advertisement , i just want to talk about safety of playing laser pointer .   Don't play laser pointer careless !

Thanks for reading !

     Thanks the god , I don't know how to express my exciting of new site start working , let me show some history :

      Screambuy.com started to consider to make in 2005 , at that moment , we were not good at site building , but we had lots of interesting products to sell , we studied hard , then i remember in the beginning of 2006 , we made it . But it was just a simple site , which just showed products online , but it was enough for us to tell old customers what we had . Unfortunately , We still had to pay more times on excel orders which is for negotiation , confirmation , proceeding etc. 

      About the beginning of 2007 , we decided to change , so that customer can buy small quantity products on site directly , and we paid times on big orders . at that time , we didn't know any site building code yet , we tried to use simple software to build , So Screambuy.com's first shop was simple , slow , and complicated . we had lots of good ideas , but could not realized .  

      The 1st site was changed into 2nd site because we can not bear of too much troubles on 1st one . I remember it should be Jul. - Sep. of 2007 . Again we paid lots of time to revise , but at last , the new site does not work for a long time , because freight is a headache to handle . The 2nd one does not support oversea freight caculation . 

      We asked some website design guys , they lead us to change again , in mid of 2008 , the 3rd site start working , which was good enough for us to sell lots items on site , we achieved our object , customers were satisfied it too . For a long time , we supposed that was good enough , no need to change . The 3rd one worked for 1 - 2 years , when total products reach 2000 pcs , we found that it was hard to have a good management on big quantity products , things started to go stuck . We dare not to change the site easily because too much working and unknown what happen on new design site . 

      I thinkwe started to consider 4th design in mid of 2009 , at last a talent gave us an idea of how to change , but it is a brand new system and need hard coding . It was almost impossible for us to upgrade into it .  But we didn't give up , we start to learn website coding , design , server info from the first step . It should be 6 months so that we knew how to make . Then we make a local site ( work in my computer only ) , install different module to test stability , put into some products to have trial test , consider how it works when putting on server , put into lots of products to test stability again ....  Of course , thousands of bug comes , we have to debug one by one , or sometimes , even can not solve it , we have to find other ways to try .

       I remember we started to make mirror site on internet during mid of 2010 , which we supposed it was good revise enough for future development . Then , those thousands of products have to move one by one into this new site . I don't know how to explain what a hard working . 

       Until today , one day before China middle Autumn , although there are lots of products we don't upload yet , we decide to let 4th designed new site instead of old 3rd one ! 

       I believe this 4th site should be far more better than before one , and there are many great functions . I will tell you in later topics . 

       Hope that every one will like it , if found errors , please contact us .  Thanks for reading !

Vinsion

Owner of Screambuy.com